With regard to the existing light sources that generate white light for lighting, from initial incandescent lamps and fluorescent lamps to relatively new LED light sources that are currently used, these light sources mentioned above generally cause, when generating white light, that the white light generated thereby exists certain deficiency in performance due to the limitation of factors, such as the compositional design or the structural design of the light sources per se.
For example, the existing white-light LED commonly used. The LED (light-emitting diode) device, as a novel solid light source, not only has the advantages of a low power consumption, a small volume, a fast response speed, a long working life, being liable to light adjustment and colour adjustment, being energy saving and environmentally friendly, etc., but also gains significant advantages over traditional light sources, such as an incandescent lamp and a fluorescent lamp, in terms of production, manufacturing and applicability, and therefore it has obtained considerable developments since it was born in the sixties. At present, the LED device has been widely applied in a plurality of fields of lighting, such as street lamp lighting, landscape lighting, large screen display, traffic lights and interior lighting.
The existing LED light sources are mainly obtained by exciting yellow luminescent powder with blue light, or exciting red, yellow and green luminescent powder with a blue light chip, while the traditional process is to mix the yellow luminescent powder and silica gel and then coat the mixture on the blue light chip, and cure the silica gel by heating, or to make the LED device by arranging the luminescent powder and the blue chip apart.
However, it can only be determined whether an LED device formed by means of a traditional process complies with the performance requirements, i.e. whether the performances, such as a colour temperature, a colour rendering index, a colour tolerance, a fluctuation depth, light effect and an light emergent angle, are within target ranges, by testing a finished LED light source, and if the performances exceed the target ranges, the device is an unqualified product. With regard to such an unqualified product, the existing manufacturers generally cannot effectively process it.